The phenotypic expression of a transgene in a plant is determined both by the structure of the gene or genes itself and by its or their location in the plant genome. At the same time the presence of the transgenes or “foreign DNA” at different locations in the genome will influence the overall phenotype of the plant in different ways. The agronomically or industrially successful introduction of a commercially interesting trait in a plant by genetic manipulation can be a lengthy procedure dependent on different factors. The actual transformation and regeneration of genetically transformed plants are only the first in a series of selection steps, which include extensive genetic characterization, breeding, and evaluation in field trials, eventually leading to the selection of an elite event.
The unequivocal identification of an elite event is becoming increasingly important in view of discussions on Novel Food/Feed, segregation of GMO and non-GMO products and the identification of proprietary material. Ideally, such identification method is both quick and simple, without the need for an extensive laboratory set-up. Furthermore, the method should provide results that allow unequivocal determination of the elite event without expert interpretation, but which hold up under expert scrutiny if necessary. Specific tools for use in the identification of elite event EE-GM3 and EE-GM1 or EE-GM2 in biological samples are described herein.
In this invention, EE-GM3 has been identified as an elite event from a population of transgenic soybean plants in the development of herbicide tolerant soybean (Glycine max) comprising a gene coding for glyphosate tolerance combined with a gene conferring tolerance to 4-hydroxy phenylpyruvate dioxygenase (HPPD) inhibitors, each under control of a plant-expressible promoter.
EE-GM1 and EE-GM2 have previously been identified as elite events from a population of transgenic soybean plants in the development of herbicide tolerant soybean (Glycine max) comprising a gene coding for glufosinate tolerance under control of a plant-expressible promoter and are described in WO2006/108674 and WO2006/108675 (both publications herein incorporated by reference).
Soybean plants comprising a herbicide tolerance gene have been disclosed in the art. However, none of the prior art disclosures teach or suggest the present invention.
It is known in the art that getting a commercial herbicide tolerant elite transformation event in soybean plants with acceptable agronomic performance, with no yield drag, and providing sufficient herbicide tolerance, certainly to 3 different classes of herbicides, is by no means straightforward.
Indeed, it has been reported that the first soybean event (event 40-3-2) released on the market with herbicide tolerance, had a significant yield drag compared to (near-)isogenic lines (Elmore et al. (2001) Agron. J. 93:408-412).
Also, Optimum™ GAT™ soybeans (event 356043) were developed to combine tolerance to glyphosate with tolerance to ALS herbicides, but it has been reported that these soybeans were not meeting the standards for glyphosate tolerance by itself (without combination with another glyphosate tolerance soybean event (such as event 40-3-2).